Mid-tone Contrast Enhancement of Photographic Images

The visual appearance of an image can often be improved by modifying the contrast in part of the tonal range. This Demonstration lets you change the mid-tone contrast of an image by applying a function to a limited range of intensities.

The tone curve shows the relation between the original and the modified pixel values.

The target range for the contrast change is marked by the shaded zone in the tone curve. You can set this range by choosing its midpoint and width with the sliders. Setting the number of interpolation points and the interpolation order defines the smoothness of the contrast transitions.